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Statistical assessment of H/A target decomposition theorems in radar polarimetry

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science china(Information sciences) 2010年第2期53卷 355-366页

作者： LIU Tao 1,2 , HUANG GaoMing 1 , WANG XueSong 2 & XIAO ShunPing 2 1 school of electronic engineering, Naval university of engineering, Wuhan 430033, china 2 school of electronic science and engineering, national university of defense technology, changsha 410073, china school of electronic engineering Naval University of Engineering Wuhan China school of electronic science and engineering National University of Defense Technology Changsha China

Target decomposition (TD) theorems have been widely applied in radar polarimetry, serving as the bridge between radar measurements and the physical parameters of a scatterer. The H/A target decomposition is one of the most suitable tools for performing data interpretation in the study and characterization of natural scatters. In this paper, the statistics of the parameters of eigenvalue, eigenvector and H/A have been analyzed via a novel method, and the probability density functions (PDF) have been obtained. It is pointed out that all these parameters can be seen as asymptotically nonbiased with respect to the number of looks. In order to reduce the biases for a small number of looks, a novel estimator for the parameters has been proposed. We give the basic theorems for accurate estimation of parameters.

关键词： target decomposition theorems H/A characteristic parameters statistical analysis MLE

Nonstationary clutter suppression for airborne conformal array radar

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science china(Information sciences) 2011年第10期54卷 2170-2177页

作者： DUAN KeQing 1,2,XIE WenChong 2 & WANG YongLiang 2 1 school of electronic science and engineering,national university of defense technology,changsha 410073,china 2 Key Research Lab,Wuhan Radar Academy,Wuhan 430019,china school of electronic science and engineering National University of Defense Technology Changsha China Key Research Lab Wuhan Radar Academy Wuhan China

The essence of nonstationary clutter for airborne radar with conformal antennas array (CAA) is analyzed,and an angle-Doppler compensation method for clutter suppression is *** with the uniform linear antennas array (LAA),the clutter angle-Doppler spectrum distribution of CAA should be described in four-dimension space,i.e.,three-dimension space and time,because the elements of CAA are distributed in three-dimension *** to this theory,the clutter nonstationarity for airborne radar with CAA is firstly analyzed and the nonstationary nature of it is *** an improved STAP method for airborne radar with CAA is proposed,and it compensates for the mainlobe clutter in four-dimension frequency ***,the simulation results show the effect of the novel method.

关键词： conformal antennas array (CAA) space-time adaptive processing (STAP) nonstationarity clutter suppression

正态分布未知参数的联合序贯验后加权检验方法

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系统工程与电子技术 2004年第6期26卷 744-746,805页

作者：申绪涧戚宗锋汪连栋王国玉国防科技大学电子科学与工程学院湖南长沙410073 中国人民解放军河南洛阳471003

在进行抽样试验时,采用传统的假设检验方法进行决策所需的样本容量通常是比较大的,而充分利用在进行抽样试验之前所能获得的关于总体分布未知参数的验前信息,在Bayes理论的基础上,采用序贯验后加权检验方法可以有效地减小试验所需的样... 详细信息

在进行抽样试验时,采用传统的假设检验方法进行决策所需的样本容量通常是比较大的,而充分利用在进行抽样试验之前所能获得的关于总体分布未知参数的验前信息,在Bayes理论的基础上,采用序贯验后加权检验方法可以有效地减小试验所需的样本容量。对正态分布总体的均值与方差参数均未知时的联合序贯验后加权检验方法进行了深入分析,给出了在抽样试验之前确定假设检验问题所需样本容量和决策阈值的计算方法,并结合雷达探测距离的以往实际试验数据和结果进行了对比分析,验证了该方法在减小样本容量及提高试验效费比方面的有效性。

关键词：贝叶斯理论正态分布序贯检验样本容量

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远距离支援干扰与机载预警雷达的对抗仿真

系统仿真学报 2004年第9期16卷 2003-2005,2008页

作者：申绪涧李益民汪连栋戚宗锋国防科技大学电子科学与工程学院中国人民解放军63880部队

机载预警系统(AEW)是现代战争中必不可少的电子支援系统,远距离支援干扰(SOJ是对抗AEW的一种有效手段,尤其是采用多部干扰机合理布站时干扰效果更佳。本文对SOJ与AEW的对抗进行了建模与仿真,通过对仿真结果及相应图表的分析,对比了不同... 详细信息

机载预警系统(AEW)是现代战争中必不可少的电子支援系统,远距离支援干扰(SOJ是对抗AEW的一种有效手段,尤其是采用多部干扰机合理布站时干扰效果更佳。本文对SOJ与AEW的对抗进行了建模与仿真,通过对仿真结果及相应图表的分析,对比了不同情况下压制扇面的变化情况。

关键词：远距离支援干扰机载预警系统对抗仿真

基于OpenGL的地形及无线电场强预测三维仿真

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山西电子技术 2009年第5期 72-73页

作者：张琦赵育才凯迈(洛阳)电子有限公司河南洛阳471000 国防科技大学电子科学与工程学院湖南长沙410073

三维地形可视化技术是地理信息系统和虚拟现实中的核心技术。本文介绍了数字高程模型的基本原理和如何绘制三维地形;利用MFC与OpenGL编程技术,重点论述了如何实现场强预测结果的三维显示。

关键词：数字高程模型 OpenGL 场强预测

A new satellite to satellite tracking algorithm from Doppler-shifted frequency measurements

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Progress in Natural science:Materials International 2007年第10期17卷 1226-1234页

作者： Li Qiang, Guo Fucheng and Zhou Yiyu(school of electronic science & engineering, national university of defense technology, changsha 410073, china) school of electronic science and engineering National University of Defense Technology Changsha 410073 China

A new satellite to satellite tracking (SST) algorithm from Doppler-shifted frequency measurements is proposed. The estimation principle is demonstrated and the mathematic model of SST is established. The state estimation methods for a user (the cooperative case) and target satellites (the non-cooperative case) are presented based on particle swarm optimization (PSO). The Cramer-Rao lower bounds (CRLB) are deduced as well. Performance of the new algorithm is validated through computer simulations, which proved that the proposed method is effective in terms of the estimation quality compared with CRLB and superior in accuracy to the Bearings-Only (BO) method in almost all simulation cases except for the case that an enough long tracking arc-length is obtained for a user satellite.

关键词： satellite to satellite tracking (SST) Doppler-shifted frequency (DSF) Space Surveillance Network (SSN) particle swarm optimization (PSO).

A type of M2 -transmitter N2 -receiver MIMO radar array and 3D imaging theory

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science china(Information sciences) 2011年第10期54卷 2147-2157页

作者： ZHU YuTao & SU Yi school of electronic science and engineering,national university of defense technology,changsha 410073,china school of electronic science and engineering National University of Defense Technology Changsha China

With two-dimensional synthetic apertures,a wideband radar array can realize 3D imaging of air targets,but this needs large numbers of antenna ***,when the transmitting frequency is very high,the interval of array elements makes it hard to fit the available space,which makes the imaging resolution *** paper proposes a type of M 2 -transmitter N 2 -receiver multiple-input multiple-output (MIMO) radar,which is equivalent to a rectangular radar array with (M N) 2 T/R antenna elements based on phase center approximation theory,and which can realize the 3D imaging of air *** 3D imaging theory and MIMO inverse synthetic aperture radar (MIMO-ISAR) 3D imaging theory are also proposed in this paper,and two simulations are given to show their validity.

关键词： MIMO radar array phase center approximation 3D imaging ISAR

Focusing transform-based direction-of-arrival method exploiting multi-cycle frequencies

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Progress in Natural science:Materials International 2005年第6期15卷 491-495页

作者： HUANG Zhitao*, JIANG Wenli and ZHOU Yiyu(school of electronic science and engineering, national university of defense technology, changsha 410073, china) school of electronic science and engineering National University of Defense Technology Changsha 410073 China

When single cycle frequency is employed, the existing spectral correlation-signal subspace fitting (SC-SSF) algorithms usually contain two disadvantages: those single-cycle estimators cannot reach the best performance; it is inconvenient to be applied in practice since the right cycle frequency has to be selected. Based on the Jacobi-Anger expansion and the idea of focusing transform, a new approach exploiting multi-cycle frequencies of cyclostationary signal is discussed in this paper. Simulation results demonstrate the effectiveness of the new method.

关键词： cyclostationary signal direction-of-arrival multi-cycle frequencies focusing transform.

Sidelobe reduction based on spectrum reshaping in microwave imaging

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science china(Information sciences) 2011年第1期54卷 204-212页

作者： WANG HuaiJun,SU Yi,XU HongBo & ZHU YuTao school of electronic science and engineering,national university of defense technology, changsha 410073,china school of electronic science and engineering National University of Defense Technology Changsha China

Sidelobe artifacts are a common problem in image reconstruction from finite-extent Fourier data obtained by microwave imaging *** order to enhance the image quality,sidelobe reduction must be *** the sidelobe reduction in microwave imaging as the research subject,this paper presents Fourier imaging technique *** the point spread function is obtained through Fourier inversion of rectangular spectral support data and the changing effect of sidelobe direction due to reshaping spectral support is *** reshaping makes that the sidelobes of two Fourier images do not *** on the idea of separating sidelobes from mainlobe,a nolve method that reduces sidelobe levels while maintaining the imaging resolution is *** performance of this method is ***,the simulated and measured data of typical microwave imaging systems such as synthetic aperture radar(SAR),inverse synthetic aperture radar(ISAR)and real aperture radar are used to demonstrate the validity of the proposed method.

关键词： microwave imaging Fourier imaging sidelobe reduction spatial spectrum point spread function